High-frequency signaling



1,624,208 April 1927' P. M. J. BOUCHEROT HIGH FREQUENCY SIGNALING Filed Aug. 29, 1921 1 EDE f/gi

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P.M.J.BOUC H EROT 1 w afiwyw Patented Apr. 12, 1927.

PAUL MARIE JOACI-IIM BOUCHEBOT, F PARIS, FRANCE.

HIGI-LFREQUENCY SIGNALING.

Application filed. August 29, 1921, Serial No. 496,692, and in France August 27, 1915.

(GRANTED UNDER THE PROVISIONS 8F THE ACT 03? MARCH 3. 1921, 41 STAT. 11., 1313i) The present invention relates to a method of producing high frequency currents by sparks.

In methods heretofore employed for this purpose, the number of the sparks is always small as compared with the number of the periods of the generated current and there is no simple relation between these two numbers. The basic phenomenon is that of the oscillating discharging or charging and this is the phenomenon that determines the number of the periods of the current generated. The oscillations are free and the charge which merely affords passage to the current has a duration parallel to that of the phenomenon, i. e. its duration is re stricted to a more or less large number of periods of the current and which number is not necessarily entire.

According to the present invention, the number of the sparks is equal to the number of the periods of the generated current. Every time a spark is produced, the resistance of the spark gap is reduced and this periodic variation of the resistance is utilized for producing forced oscillations. i. e. oscillations having a frequency that is not determined by the frequency of the oscillating circuits proper, but by the frequency of the sparks.

In view of the fact that a large number of sparks must be produced within a given time (20,000 to 500,000 per second for the ordinary frequencies used in wireless telegraphyl this obiect cannot be attained with out difficulties. but in accordance with the invention the difficulties are avoidable even in the case of the highest frequencies.

In the accompanying drawings:

Fig. 1 is a lateral elevation of an apparatus embodying the present invention.

Fig. 2 is an end view of the same apparatus.

Fig. 3 is a schematic representation of a circuit arrangement.

Figs. 4c and 5 represent modifications of the circuit arrangement of Fig. 3.

In Figs. 1 and 2, the sparker, which may be referred to as a synchronous sparker, is composed of a rapidly rotating disc 1) carrying a large number of teeth P which pass in proximity to one or more stationary electrodes E. This disc is mounted on a flexible I shaft A, the mechanical control of which may be accomplished in any suitable manner. With a tangential speed of 300 meters per second and a distance of 5 millimeters between the teeth, a frequency of 60,000 periods per second may be attained, which is a frequency common in large wireless telegraph stations.

If a single electrode is used a brush may be provided on the shaft to prevent the passage of the current through the bearings. If double tension or voltage can be used, preferably two electrodes E will be employed, mounted in such a manner that the sparks are produced either on the exterior circumference or on one or on both sides of the disc but at the same time. The latter arrangement is illustrated in Fig. 1. The wind produced by the teeth revolving at high speed makes the provision of a special spark extinguisher usually unnecessary. Such extinguisher may, however, be used for the purpose of further increasing the efficiency of the sparker. For this purpose the electrodes E may be tubular and air may be conducted therethrough. Separate extinguishers may, however, be used for this purpose.

The power may be supplied from a direct current source, dynamo or storage battery, or a rather low frequency alternating current source (40 to 1000 periods per second). In the latter case there is a time during'a portion of each alternation when high frequency production may be arrested. However, this disadvantage may be compensated if desired, in other ways. as by controlling the current supplied by means of self induction coils; or utilizing the low frequency resonance for increasing the tension at the terminals of the s'oarker when the spark is drawn and to obtain a sturdy machine.

In the circuit arrangement shown in Fig. 3; E is the sparker, B a storage battery, A the antenna and T the ground. By means of the resistance R, the current supplied to the antenna may be controlled at will, Notwithstanding the fact that the frequency of the oscillations produced is determined by the sparker and not by the frequency of the antenna, it is advisable to synchronize them for the purpose of obtaining the maxi mum of current and power in the antenna. This may be readily accomplished either by varying the speed of the sparker, 'or by introducing into the antenna tuning inductance or capacity. However, such arrangements are not indispensable and are not illustrated in Fig. 1. The signals may be sent in any desired manner, for example, by opening of the battery or the antenna circuit, or by manipulating the electrodes of the sparker, or by short circuiting the sparker, etc. However, it should be noted that no matter which sending method is adoptechthe speed of the sparker does not change like the speed of an alternatorwhich is successively charged and discharged at irregular intervals. In this manner a great disadvantage is obviated. This holds good for any other source of energy in the place of the storage battery. In case such source is a machine, its speed may vary, but this does not necessarily cause variations in the speed of the sparker.

In order to purify the high frequency current, the supply circuit may be acted upon by induction by giving to the different circuits distinct frequencies equal to that of the sparker.

In the circuit arrangement shown in Fi tan alternator D is used. E the sparker, A the antenna and T the ground. Circuits L C L C and L, C are tuned in the above described manner. The self induction L and the capacity C are connected in shunt before the 'sparker for absorbing the variations in the high frequency potential which might damage the alternator. The self in duction L and the capacity C, together are connected in shunt with the alternator and serve for the absorption of high frequency current that might pass through the alterna tor. The self induction coil L has an iron core, and in case of low frequencies it serves both for limiting the current produced to the desired value and being in more or less perfect resonance with the capacity 0,, low frequency resonance, for producing a superpotentialuseful for-the drawing of the spark. Furthermore, the self induction of the alter nator acts in the samemanner.

In the above described arrangement, the primary winding of the 'connection coupled to aerial is connected in shunt with the sparlcer. It may be connected in series, as shown in 5. In this figurethe current source is a direct current dynamo. In this modification the sparker carries two systems of electrodes "E E and E E arranged in such a manner that one set gives sparks when the sparks are extinguished in th other set. @neof these systems (E, E is inseries with a primary winding L and the other (E P1,) with another primary L The two systems have 'a common secondary L with which the antenna A anda suitable capacity C, are connected. In this arrangement, the pulsating currents in the two primaries are opposed toeach-other and the windings of each being in the opposite direction, they aid each other in acting on the secondary.

The same result may be obtained. with three or a larger number of electrode systems associated with a corresponding number of primaries, the electrode systems being suitably separated on the circumference of the sparker. Further description of systems using a plurality of electrodes is not considereu essential.

Obviously, this arrangement using two or more electrodes may be applied to the shunt connection of the sparker shown in Fig. 4.

By reversing one of the primaries L, or L and suitably adjusting the capacity in the secondary L a current will be obtained in the secondary winding the frequency of which is double that of the current that would be obtained by a single system of electrodes. However, it is necessary that the spark extinction be sufficiently energetic when the frequency is increased to interrupt the current for a longer period of time in each primary.

Obviously, this arrangement may also be utilized with the circuit shown in Fig. 4. The arrangement fordoubling the frequency may be combined with the arrangement hav ing two opposed coils, i. e. four primaries may be provided for doubling the frequency and direct current be supplied e:-:'clu- .sively from the source.

By using three or more brushes or sets of brushes and coils the frequency may be correspondingly multiplied by an "extension of the modification of Fig. 5 in which the number of the electrodes is multiplied.

Furthermore, with any of the arrangements, the number ofthe electrodes and primary circuits may be multiplied for the purpose of supplying more power, by utilizing more of the periphery of the sparker.

Having described my invention, what I claim is:

1. In high frequency generator signaling systems, the combination of a circuit containing asource of power, a sparker adapted to interrupt said source at a radio frequency, a circuit connected to said .sparker tuned to substantially said frequency of interruption, and an antenna tuned to substantially the same frequency coupled to said last mentioned circuit.

2. ln high frequency generator signaling systems, the combination of a circuit containing a source of power, a rotating spark wheel having a large number of teeth, a plurality of pairs of brushes connected to said circuit adapted to cooperate with the teeth of said wheel to interrupt the current in said circuit at a radio frequency, andan inductance coil associated with one of each pair of said rushes and in series therewith.

3. Inhigh frequency generator signaling systems, the combination of a source of current, a circuit connected to the terminals of said source comprising two inductances, a brush connected to each of said inductances and a sparker connected in said circuit having a plurality of teeth adapted to cooperate to interrupt the current at a radio trequency and to pass current alternately through said coils,

a. In high frequency generator signaling systems, the combination of a source of current, a circuit connected to the terminals of said source comprising tWo inductances, a brush connected to each of said inductances, and a sparker connected in said circuit having a plurality of teeth adapted to cooperate to interrupt the current at a radio frequency and to pass current alternately through said coils and a utilization circuit tuned to the frequency of interruption cou- 20 pled to said coils.

PAUL MARIE JOACHIM BOUCHEROT. 

